Pattern controlled machine tool



May 24, 1949. BALL 'r L 2,471,097

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May 24, 1 949. A.-H. DALL EI'AL PATTERN CONTROLLED MACHINE TOOL.

Filed July 39, 1944 r 7 Sheets-Sheet 4 Array/Y5K May 24, 1949. A. H. DALL ETAL PATTERN CONTROLLED MACHINE I'OOL 7 ShOOtS-ShGOt 5 Filed July 29, 1944 May 24, 1949. A- H. DALL mu. ,47 ,097

v PATTERN CONTROLLED MACHI NE TOOL Filed July 29, 1944 7 Sheets-Sheet 7 DEPT H TRAC ER Patented May 24, 1949 PATTERN CONTROLLED MACHINE TOOL Albert H. Dali and Herman Horlacher, Cincinnati,

Ohio, assignors to The-Cincinnati Milling Machine Co., Cincinnati, Ohio, a corporation of Ohio Application July 29, 1944, Serial No. 547,200

1 34 Claims. This invention relates to machine tools and more particularly to improvements in automatic pattern controlled milling machines.

One of the objects of this invention is to provide a pattern controlled milling machine which is operable automatically to produce threedimensional surfaces on a work piece in a single continuous automatic operating cycle of the machine without attention on the part of the operator once the operating cycle has been initiated.-

Another object is to provide an improved method ofautomatic die-sinking whereby threedimensional surfaces may be rapidly and efficiently formed on a work piece without repositioning or otherwise moving the work piece or changing the operating conditions of the machine to thereby insure a high degree of fidelity between the pattern and the work piece with maximum productive output for the machine.

A further object is to provide an impro d r ss indexing arrangement in conjunction with reversible longitudinal feeding movements for effecting an automatic progression scanning operation on a three-dimensional work piece at any desired angular relationship to the direction of movement of the operating members of a pattern controlled milling machine.

It is also an object to provide indicating means in conjunction with the aforementioned automatic progression scanning arrangement which shows whether the tracer and cutter are operating in longitudinal feeding or cross indexing progression movements and in what direction said movements are taking place.

A further object is to provide an arrangement in which the feed rate of the longitudinal movement and the amount of cross indexing movement for the automatic progression operation may be independently adjusted and regulated.

It is also an'object to provide in a pattern controlled milling machine a profile tracer and an associated pattern as the sole means to initiate and control the automatic progression scan- 'ning operation on a work piece.

Still another object is to provide selective control means which may be readily adjusted to permit the machine to perform manual profiling or diesinking, normal automatic profiling, or automatic progression scanning die-sinking opera-- that any modifications may be made in the exact structural details there shown and described, within the scope of theappended claims, without invention.

Referring to the drawings in which like reference numerals indicate like or similar parts:

Figure 1 is a right hand side elevational view from the operators position of a multiple spindle pattern controlled milling machine incorporating the features of this invention.

Figure 2 is a front elevational view of the machine shown in Figure 1 with the work and pattern. frames removed from the work table of the machine.

Figure 3 is an enlarged fragmentary section on the line 33 of Figures 1 and 2.

Figure 4 is a diagrammatic section of a portion of the hydraulic progression control mechanism on the line 4-4- of Figures 1 and 3 showing one operative position of the parts of this mechanism.

Figure 5 is a fragmentary enlarged'vertical section on the line 5-5 of Figure 3.

Figure 6 is a diagrammatic section of a portion of the hydraulic control mechanism similar to that of Figure 4 showing another operative position of the parts of this mechanism.

Figure '7 is a diagrammatic section of a portion of the hydraulic progression control mechanism of Figures 4 and 6 showing still another operative position of the parts.

Figure 8 is a fragmentary enlarged view of a portion of a work piece to be machined showing the preliminary profiling operation preparatory to initiating the automatic progression machining cycle.

Figure 9 is a section through the workpiece on the line 9-9 of Figure 8.

Figure 10 is a diagrammatic view showing the path of travel of the tracer and cutter relative to the pattern and work during the automatic progression cycle.

Figure 11 is an enlarged face view of an exemplary work piece having a series of differently oriented portions to be machined.

Figure 12 is an enlarged diagrammatic view 0 the profile tracer direction control hand wheel and the automatic progression setting knob showing their relative positions when effecting horizontal longitudinal scanning feeding movement with downward progression movement in' machining a work piece.

Figure 13 is a view similar to Figure 12 showing a, setting for effecting angular automatic progression scanning of a work piece.

Figure 14 is a view similar to Figures 12 and 13 showing still another angular setting for eflecting progression scanning of a work piece in still another angular direction.

Figure 15 is an enlarged fragmentary view, partly in section on the line Il 5 of Figure 1.

Figure 16 is a diagram of the hydraulic control circuit of the machine.

For illustrative purposes this invention is shown applied to a multiple spindle pattern controlled milling machine comprising a base 28 to the rear portion of which is rigidly fixed the column 2| having vertical guideways 22 upon which is reciprocatably mounted the saddle 23 and which may be actuated in vertical movement by a suitable fluid pressure motor or cylinder 24 which is attached to the saddle and has a piston 25 and a piston rod 28 whose outer end is connected by a bracket 21 fixed to the column 2| of the machine. On the saddle 23 are guideways 28 upon which is mounteda spindle carrier 28 which may be actuated' in horizontal movement on the ways 28 by means of a suitable fluid pressure motor or cylinder 30 having a piston 3| and a piston rod 32. The cylinder 38 is rigidly held to the saddle 23 and the piston rod 32 is connected by a suitable bracket 33, Figure 2, to the spindle carrier 29. In the spindle carrier is journaled, in this particular illustrative example, a series of three 1 cutter spindles 34 each of which may be driven at appropriate cutting speed by a suitable power transmission of any conventional design.

011 appropriate guideways 35 formed on the top of the base 28 is mounted the work and pattern table 38 for horizontal reciprocating movement perpendicular to the direction of movement of the saddle 23 and spindle carrier 28. The table 36 is actuable on the ways 35 by a fluid pressure motor or cylinder 3'! fixed in the base 28 and having a piston 38 connected through a piston rod 38 to bracket 48 mounted on the table 38. In this way three directions of perpendicular movement are provided by the saddle 23, spindle carrier 28, and table 38.

' Mounted rigidly to the top of the table 38 is the work holding frame 4| by suitable clamping bolts 42. Mounted on theframe 4| is a series of work pieces or die blocks W having work cavities W-l, W-2 and W3, Figures 1 and 1 1, to be machined by the repective cutters 0 carried in the work spindles 34 as best seen in Figure 1. On top of the frame 4i is an auxiliary frame 43 which carries the profilepattern 44 and the depth control pattern 45. r

On an appropriate bracket 48 mounted on the spindle carrier is a profile tracer having a housing 41a with a universally mounted tracer finger 48 journaled therein which operates in the various profile openings 48 provided in the usual mannerin the profile pattern 44, Figure 1. These openings 49 correspond to the desired outline or profile of the work surfaces to be machined. Also mounted on the bracket 48 carried by the saddle 29 is a-depth tracer, indicated generally at 50, having a tracer finger 5! which operates in appropriate contact with the depth pattern 45.

Generally in this arrangement the profile tracer head 48a. controls the simultaneous relative movement of the saddle 23 and the table 38 for performing 360 profile tracing movements while the depth tracer 58 having tracer finger 5| may be operated simultaneously with the profile tracer 48a to eifect the third dimensional depth control by controlling the horizontal movement of the spindle carrier 28 to and from the work pieces and patterns on thetable 38.

In order to carry out the machining of such threedimensional surfaces, such as the surfaces W-l, W-2 and W--3 of the work pieces W in an efilclent and automatic manner it is first preferable to effect a 360 profiling out such, as indicated at 52 in Figures 8 and 9, by allowing the profile tracer 48 to automatically follow around the profile pattern portions 48 of the pattern 44 and while also utilizing the depth tracer 5| if necessary. In this way the profile outline surface 53 of the work is established and completed, leaving a central portion 54 to be removed to ultimately produce a three-dimensional surface, for example,

as shown at 55 in Figure 9.

The invention of this case is particularly directed to a machine capable of automatically producing the three-dimentional surface 55 by the removal of the portion 54 from the work W. This operation is accomplished in an automatic manner by a back and forth longitudinal feeding or scanning movement of the cutter across the section 54 while intermittently cross indexing the cutter at right angles to this longitudinal feeding movement at the completion ofeeach stroke so as to ultimately progress across the entire surface to remove the portion 54 down to the desired three-dimensional surface 55. With the present arrangement, the cross indexing and longitudinal feeding movements are under all conditions maintainedwithin the confines of the outline profile of the actual work surface to'be machined. It is also possible with this arrangement to effect the longitudinal feeding movements and the cross indexing movements in any desired angular direction at any time by minor adjustments of the apparatus without requiring the movement of the work in the machine or any reorganization of the machine set-up. This type of machining operation comprising the automatic sequential operation of cross indexing movement and longitudinal movement to scan a three-dimensional work surface may be known as an automatic progression scanning operation. When the cross indexing and longitudinal movements take place in .angularly related directions to the directions of movement of the machine members or slides, the operation may be termed an automatic angular progression operation.

In Figure 10 is diagrammatically illustrated a typical path of cutting movement as effected in the present arrangement in which the tracer and cutter are feeding longitudinally to the right along the horizontal line 58 during which time the profile tracer finger 48 is not contacting any pattern but is moving in space while in undeflected condition. The depth tracer 5| may be operating in a conventional way in engagement with the depth pattern 45 to effect the proper in and out positioning of the spindlecarrier 29 relative to the work pieces and pattern 45. As the profile tracer finger 48 arrives at the point 51 it engages the surface 53a of the profile pattern 44 corresponding to the work portion W-l to be machined and is deflected causing the tracer head 48a to automatically rotate clockwise 90 to thus cause the cutters and tracer to move in cross feeding direction along the line 58, the length of the travel along the-line 58 being determined by an arrangement entirely independent and unafiected by the rate of feed in traveling along the line 58.

when the point 59 is reached, automatic means again rotates thetracer head clockwise another and again establishes longitudinal feedin eflect another cutting stroke across the work surface. When the other side of the profile pattern surface 58a of the profile pattern 44 is reached the tracer head is automatically-rotated counterclockwise 90, cross feeding then takes place along the line 5811, Figures and 11, for a cross movement of a deflnite predetermined amount-independent of the feed, and finally-the tracer head is-rotated counterclockwise automatically another 90 to again effect the longitudinal feeding motion to the right along the line 82 to ultimately cover the entire work surface 55 automatically.

In certain'instances the work surface may have aconverging or reentrant type of surface profile, such as shown at the point 63, so that as the tracer 48 strikes the surface 58a atpoint 88 while traveling along-line 84 it must rotate the tracer 7 head more than 90 clockwise before cross feeding movement takes place to prevent the cutters from otherwise cutting into and beyond the desired surface 53 of the work. Automatic mechanism is provided so that when the tracer is moving along the line 84 and is deflected at the point 83 the tracer head will rotate not only through the 90 movement but will automatically continue until it arrives at a suitable direction of movement, indicated by the arrow 65, sufficient to properly clear the work surface 58 at that point before the cross feeding movement takes place. The cross feeding then takes place in the direction of the arrow 68 until the tracer has 'arrived at the point 88 whereupon automatic means is further provided for finally rotating the head the remaining portion of its 180 clockwise rotation from the point to eflect the proper direction of longitudinal feeding movement along the been scanned by this automatic progression machining operation.

- It is obvious that in order to get the maximum production'from such a machining operation it is preferable to 'minimize as much as possible take care of such condions with the result that great loss of time results in having to conflne the scanning movements to directions parallel with the movable machine members.

with the present arrangement, however, by the mere-adjustment of a control knob the operator may readily effect the automatic progression movement, as described above. inFigure 10, in any angular direction such as that shown at W! and W8 in Figure 11 without in any way readiusting the work piece 'in the machine or otherwise modifying the general operation of the machine set-up. In this way the number of reversals required to scan the entire work surface is reduced to a minimumby accommodating the automatic progression to the greatest longitudinal extent of the work surface being machined. a J

In order to obtain the above method of operation, it is preferable to utilize a tracer head construction having the tracer finger 48 so as toeffect I 360 profiling movements in a'manner. for exthe necessary reversals of direction of longitu- .dinal feedingmovement of the tracer and cutter 'scanned by horizontal movement as shown because the greatest longitudinal extent of this work surface is in a horizontal direction. It may, however, occur that there should be work surfaces angularly'disposed as shownin W--2 and W3 in which their greatest longitudinal extent is not horizontal nor'parallel to any of the main slide movements of! the machine.

latter condition exists one of the slide membersof the machine cannot be used to effect the cross When this indexing movement unless the work piece be shifted on' the machine to bring its configuration in proper position relative to the direction of movement of the slides. In instances where there are to be a plurality of differently oriented surfaces prepared on a single work piece, such as shown in Figure 11, it is-not practical from the standpoint of ultimate accuracy and high productivity to adjust the work on the machine to ample, as set forth in, Patent 2,332,533, issued- October 26, 1943, in which arrangement there is provided a pair of reversing valves 88 and 88, Figure 16, having appropriate valve plungers ll and H actuated simultaneously by means of a direction and feed control eccentric cam 12 as the tracer head 48a is rotated to effect the 360 tracing operation. The reversing valve 88 is connected to the vertical saddle cylinder .24 by lines 13 and 14 while the reversing valve 88'isconnected by appropriate lines 15 and I8 to the table appropriate branch lines a and connected to the reversing valve 69 by appropriate branch lines 801:. A suitable pressure relief valve I'laconnected by a branch line 880 to the line 88 serves to maintain the proper desired pressure in the line 80 under all operating conditions.

Discharge from the valve 68 passes out through the return line 8| and discharge from the valve 69 passes out through the return line 82. These lines are connected to the tracer selector valve 83 which is a two-position valve having a hand" position 83a and an automatic position 83b.

the valve being shown in the hand position in Figure 16. With the tracer'selector valve 88 in the hand position 83a as shown the return lines 8| and 82 from the reversing valves .88 and 69 are connected through appropriate annular grooves 84 and 85 of the valve plunger 86 to lines 81 and 88 respectively in which are serially connected resistances 89 and 98 to regulate the discharge from the lines 8| and 82. Outflow from the resistances 89 and 90 are communicated to a line 9| which is connected to a progression selector valve 92, which is a two-position control valve having an out"'position 92a for the normal tracing operations for'the machine and an "in" position 92b for the automatic angular progression movements to be effected in the machine. The valve 92 isshown in Figure 16 in the progression in position 92!). With the'progression nular groove 93 of the valve plunger 94 to the selector valve 92 positioned in the "out position 92a the line 9| will be connected through the an-.

drain line 95 for return of fluid to the reservoir 7 I9. Thus, under these conditions fluid supply from the pump TI is controlled by the reversing valves 88 and 69 upon rotation of the tracer head and eccentric I2 to effect a simultaneous operation of the saddle cylinder 24 and the table cylinder 21 to provide a resultant universal profiling movement for the machine. The eccentric I2 may be rotated to any desired position to effect the desired resultant direction of movement by the usual hand wheel 96a upon which are indicating pointers 96b showing the direction in which the tracers and cutters are moving rela- 8 I66. in turn, is in driving engagement with a gear III appropriately connected to the tracer head and hand wheel 86a in any suitable manner so as to rotate the tracer head 48a including the operating eccentric I2, and the hand wheel 96 by power from the hydraulic motor I66. When the tracer selector valve 93 is in the automatic" position 891) and the progression selector valve 92 is in its out position 92a fluid pressure from thehydraulic pump 'II transmitted through the line 86 and the branch lines 86d and 86a to the tracer control valve 41 is reversibly connectable tive to the patterns and work. The rate of feeding is determined by the eccentricity of the eccentric I2 which may be adjustable from zero to maximum to effect any desired rate of feed in 48, the eccentric I2, and the hand wheel 96 may be automatically rotated to obtain desired directions of feedingfor automatic profiling operations. In this arrangement, as the tracer finger 48 is movedunder manual direction to engage the pattern, its deflection results in the profile tracer valve plunger 96 of the'tracer valve 41 being, displaced axially (to the right in Figure 16) so as to connect the branch pressure line 86d connected to the valve 41 through the annular groove 91 of the valve plunger 96 to a pressure output line 98 which is connected to the progression selector valve 92, and when this valve is in its out position 92a line 98 is connected through the annular groove 99 of its valve plunger 94 to a line I66 which in turn is connected to a pressure chamber I6I formed behind the plunger 86 of the tracer selector valve 83 to thereby force the plunger 86 axially (to the leftin Figure 16) moving its control lever I62 out of the detent member I63 from the hand" position 83a to its automatic position. 83b.

As a result of this automatic operation of the tracer selector valve 83, the return lines 8| and 82 from the reversing valves 68 and 69 of the saddle and table cylinders are now connected through the annular grooves 84a and 85a to the lines I64 and I65 to the profile tracer valve 41 in such a way that the annular grooves I66 and I6! formed in the valve plunger 96 and communicating with the branch line 95a of the drain line 95 serve to effect increasing or decreasing rates of flow in the return lines 8i and 82 for the saddle and table cylinders so that the greater the deflection of the tracer the greater will be the restriction to fiow out of the lines 8| and 82 and when the tracer is in its normal tracing position the desired normal flow out through lines BI and through the annular grooves 91 and III of the tracer valve plunger 96 to the respective lines I I2 and III. These lines are connected through the tracer selector valve 89 through the respective annular grooves H4 and H5 to the lines III and H8 connected to the progression selector valve 82; This valve 92 when in its fou position connects the lines III and H8 through the corresponding annular grooves H9 and I26 formed in the valve plunger 94 to the respective lines I2I an appropriate idler gear I68 journaled on a shaft I68 in the tracer housing 41a. The idler gear and I22 connected to the hydraulic tracer rotating motor I66. Thus, as the tracer 48 is deflected and underdeflected relative to its normal tracing position reversal operation of the profile tracer motor takes place to maintain the eccentric I2 and the direction of arrows 96b appropriately oriented to cause the tracer to follow the pattern automatically. The above described apparatus and its operation is fully set forth in the abovementioned Patent 2,832,533 in view of which furth'er' detailed description of the above apparatus is deemed unnecessary.

In order to arrange the machine to cut the initial profile groove 52 as shown in Figures 8 and 9, the machine is set in the automatic profiling operating condition above described with the tracer selector valve 83 in the automatic position 83b and the progression selector valve 92 in its out position.

At this tirne also the depth tracer 56 may also be put into operation by opening the stop cock 56a in the pressure supply line 869 connected to the line 86 from the main hydraulic pump II. The pressure supply line 86b is connected around the valve 69 as shown in Figure 16 by a suitable annular groove 86f to supply pressure to the line 869 which in turn is connected to the depth tracer valve 56. Suitable control lines I23 and I24 are connected to the spindle carrier cylinder 36; Re turn of fluid from the depth tracer is conducted through the drain line 95b and is by-passed around the tracer selector valve 63 by suitable annular groove 950 connected to the drain line 950! which is by-passed around the tracer valve 41 by a suitable annular groove 95c, which in turn is connected to the drain line 95a, returning fluid to the reservoir I8.

In order to effect and control the automatic progression scanning movement of the machine there is provided a combined detent and control disc cam I25, referring particularly to Figures 3 and 5, which is flxed to the same shaft I2'I by suitable key I28, and which shaft is journaled in a suitable bearing I29 in the profile tracer housing 41a and is also journaled in a bore I36 formed in a clutch sleeve member I3l which, in turn, is journaled in a suitable bearing I32 in the housing 41a. 0n the outer end of the shaft I21 is mounted a clutch disc I99 for axial movement on the bearing portion 194 (of the shaft I21) and keyed in driving relationship against the mating face Illa of the clutch sleeve member I3I. On the outer threaded end I36 of the shaft I21 is mounted a threaded clamping knob I 31 which may be rotated so as to firmly engage the surfaces I3Ia. and I33a to effect driving relationship between the clutch sleeve I3I and the clutch member'l33 in order that the shaft I21 and the sleeve I3I may be normally rotated as a unitary member. In this way, the shaft I21 may be clamped in any circumferentially oriented position relative to the sleeve I3I.

On the sleeve I3I is fixed a driving gear I39 by a suitable key I39 and which gear I38 is of the same diameter and number of teeth as the gear I I for rotating the tracer head 48a, the gear I38 also meshing with the idler gear I08 so that the disc cam I will rotate in synchronism with the rotation of the tracer head. Thus, it will be noted that when the clutch faces I3Ia and I33a are engaged by tightening the knob I31, the control cam I will rotate in synchronism with the hand wheel 96a and that by loosening the clutch clamping knob I31 the hand wheel 96a may be reoriented in any circumferential position relative to the disc cam I25 and locked into driving engagement therewith by again tightening the knob I31.

The automatic progression control disc-cam I25 has a pair of diametrically oppositely disposed detent notches I39 and I40, each of which may engage the plunger I42 of a control valve I43 carried in the tracer housing 41a. The plunger I42 is normally urged toward the disc cam I25 by the spring I to engage either one of the detent notches to hold the disc cam I25 in the position shown in Figure 4 or in the position with the detent notch I engaged by the plunger I42, as shown in Figure 7. When the disc cam I25 is held in either of these positions ,by the valve plunger I42, longitudinal scanning feeding movement is being effected and in a direction indicated by the pointers 96b on the hand wheel 96a. This feeding movement may take place in any desired direction dependent upon the relative 'circumferential setting of the hand wheel 96a with respect to the disc cam I25. The clutch member I33 which is rotatably driven at all times by the cam shaft I 21 is provided on its face I33b with the notations shown in Figures 12, 13 and 14 consisting of the two diametrically opposed "feed positions I44 and I45 and at 90 thereto the diametrically opposed progression positions I46 and I41 which cooperate with an indicating pointer I 48 on the tracer housing 41a. so as to show the position of the parts of the machine during automatic progression movements. In other words, when the feed notation I44 or I45 is in position at the pointer I48 longitudinal feeding motion is being effected in the direction indicated by the drection arrows 96b of the hand wheel 96a, and likewise when the tracer head has been rotated 90 from the feeding position the progression" indicating marks I46 and I41 are presented in position to the indicating pointer I48 to indicate that cross indexing progresson movement is tak-.

ing place and in a direction indicated by the arrows 96b of the hand wheel 96a.

' longitudinal scanning feeding movements in this horizontal direction to thereby minimze the num- 92 is moved to its in her of reversals and cross indexing movements required to complete the work to thereby increase the rapidity of production. of the machine. In order to set up the machine for automatic progression of this particular surface WI, the hand wheel 36a is rotated to the position shown in Figure 12 indicating the direction of longitudinal feed movement it is desired to effect. Having done this, the knob I31 (Figure 3) is loosened and the cam shaft I 21 and the disc cam I25 are rotated by turning the clutch member I33 so as to bring a feed position I44 intoalignment with the indicating pointer I43. The knob I31 is then tightened and with the tracer selector valve in the hand" position and the progression selector valve 92 moved to its in" position the machine is then started and the automatic back and forth feeding movement commences.

When it is desired to set up the machine for doing a work surface such as W-2 in Figure 11 again the hand wheel 96a is positioned with its pointers 96b indicating the desired back and forth longitudinal feeding movement in accordance with the angular relationship of the greatest longitudinal extent of the work surface W2. The clutch member, cam shaft I21, and disc cam I25 are again circumferentially reoriented to bring a feed" position I44 into position with the indicator I48 and the knob I31 again clamped so as to effect an angular positioning of the direction of longitudinal feed movem'ent indicated by the arrows 96b as shown in Figure 13. I

Similarly, the reorientation of the hand wheel 96a for doing a surface such as W-3 in Figure 11 is clearly indicated in Figure 14 and may be like wise accomplished by adjusting the knob I31 and reorienting the disc cam I25 relative to the hand wheel 96a.

Thus, it will be noted that any degree of automatic angular progression may be quickly set up by simply adjusting the knob I31 and setting the hand wheel 96a to the desired direction for effecting the progression and without in 'any way reorienting the work piece in the machine. Thus, any direction of angular automatic progression may readily be effected on any single work piece in the machine.

The detail arrangement of the hydraulic operating and control mechanism for effecting these results is as follows; assuming automatic progression scanning of thework surface WI, Figure 11, is to be done, the hand wheel 96a is oriented relative to the disc cam I25 as shown in Figure 3.2. The tracer selector valve 83 is positioned in the hand position and the progression selector valve position as shown in Figure 16. The machining operation is begun at a point I49, Figure 11, and proceeds in longitudinal feeding movement to the right along a line 56, Figures 10 and 11 as described. Under these conditions the profile tracer head motor I06 is rendered inoperative and the disc cam I25 and tracer head 48a are held against rotation by the plunger I42 of valve I43 engaging in the detent notch I39 of the disc cam I25. Under these conditions a motor reversing valve I50, Figure 16, for controlling the reversal operation of the tracer head motor I06 is so positionedthat pump pressure supplied through the pressure line 80 and branch line 80h to thevalve I50 is connected through the annular ,groove I5I of the valve plunger I52 to a line I53 connected to the progression selector valve 92 and through'the annular groove I20 of its valve stem 94 to the line I22 pressure derived from the hydraulic pump 11 through the line and the branch line 00i which is connected through a hydraulic resistance I50 to slim I55 connected to a control valve I50 in the tracer housing 01a having a plunger I51 normally urged toward the disccam I25 by a compression spring I51a to stop rotation oi the motor I05. The valve plunger I51 is pushed outwardly at this time by the cam point I50 01! the disc cam I25, Figure 4, so as to position the annular groove I50 to connect fluid pressure from the line I55 to a line I60 which, in turn, is connected to the control valve I40 having its plunger I02 so positioned by the detent notch I 00 in the cam I25 that its annular groove I6I permits connection of the line I60 to a line I62 which is connected through a line I60 to a pilot control valve I00. This pilot control valve I60 has a plunger I65 which is normally urged in one direction, by a compression spring I06, so that the line I60 is normally closed 01! at the annular groove I01. A branch line I001: connected to the line I60 and to the motor reversing valve I50 communicates at this time through the annular groove I60 of valve plunger I52, of valve I50 with the line I50 which is connected to the progression selector valve 02 and through the annular groove I I0 of its plunger 00 with the line I2I oi the tracer head motor I00 so that in this way fluid pressure is maintained simultaneously in both the lines I2I and I22 oi the motor I06 to prevent its rotation during the iongitudinal feeding movement. A branch line I00b oi the line I60 is also connected to the ,valve I50 and at this time is blocked off at the valve by its plunger I52. A third branch line I600 connected to the line I02 and I00 and also connected to the valve I10 in the tracer housing 01a is at this time closed oil at the annular groove "I of the valve plunger I12 01 this valve I10, the plunger I12 being moved outwardly by the cam point I10 01 the disc cam I25.

In order to compensate for leakage during the simultaneous application of pressure in the lines I2I and I22, there is also provided a supplemental supply line I10 connected to the pressure line 00 I02 iormed in the valve plunger I51 and pass around the spool I00 into annular groove I00 oi and through a' hydraulic resistance I10 and a line I10 to the line I60c so that when the motor is stopped fluid pressure will slowly bleed through the resistance I15 to make up any leakage in the motor and associated hydraulic system to keep the motor lines always fully supplied with hydraulic fluid.

The longitudinal feeding movement continues in the direction of the line 50, Figure 10, with the tracer 00 moving freely in space in undeflected condition until it engages the surface a of the template at the point 51. The tracer is then deflected to prevent escape of pressure to drain line 0511 at the annular groove 95e and to connect this pressure through the annular groove 91 in the valve plunger 06 to the line 00, and thus through an annular groove I11 01 the valve plunger 00 oi the progression selector valve 92 which is now in communication with a line I10 having one branch line I10a going to a pressure port I10 oi the control valve I50. Another branch line 1101: is connected to the control valve I00 which at this time is closed 011 by the plunger I02 of the control valve I00.

Referring more particularly to Figure 4, the valve plunger I51 or the valve I56 is here shown held outwardly by cam point I50 0! the disc cam I25 so that the spool "I of the plunger I51 is positioned relative to the port I10 so that pressure from the line I10a will enter the annular groove the valve I50 and out through a line I00 which is connected to the pressure chamber I05, Figure 18, or the motor reversing valve I50 to thereby shiit the plunger I52 01 the valve I50 axially to its other position, upwardly in Figure 16. While so shifting, the plunger I52 displaces fluid out of chamber I00 through discharge line I01, an-

nular grooves I00 and I00 in the control valve I00, into the'drai n lines 05! and 05 for return of fluid to the reservoir 10.

As the valve plunger I52 oi the motor reversing valve I50 stalls at the other end oi. its stroke, pressure builds up in the pressure chamber I05 and in the line I01 connected thereto. This pressure is connected through line I00 to the pressure chamber IOI behind the valve plunger I05 of the pilot control valve I00, shifting the plunger I65 against the compression spring I00 to cause its annular groove I61 to connect lines I60b and I00 to the drain line 05d and associated drain line 05. This action permits discharge from the, tracer head motor I00 through the line I22, the annular groove I20 in the progression selector valve 02, line I50, annular groove I5I oi the plunger I52, to the line I00b, permitting pressure coming in through the line I2I to rotate the motor I05. At this time the line I00a connected to the line I60 is closed off by the valve plunger I52 of the motor reversing valve I50.

The pressure built up in chamber I05 0! the motor reversing valve and line I00 connected to it, receiving pressure from the line I10a through the valve I56, produces pressure in the annular groove I03 formed in the valve I50 which is distributed to the annular groove I02, Figure 4, formed by the valve spools I 00 and IOI or the plunger I51, and to the annular groove I02 by the spool I00 and a smaller spool I00 operating in a reduced bore I00 formed in the valve I56. The valve spool I00 is of such width that when positioned by the cam point I50, as shown in Figure 4, there will be free passage for the fluid around the spool I00 through the annular groove I00 in the valve body I50. Thus, the fluid pressure in the chamber formed by the annular groove I02 and I02 will exert a pressure in one direction against the face of the spool IOI and against the face of the smaller spool I00 resulting in a differential axial pressure being applied to the valve plunger I51 which will hold or hydraulically latch the valve plunger against the pressure of the spring I51a in a direction away from the disc cam I25. In other words, referring to Figure 4, the plunger I51 when moved to the position indicated by the cam point I50 will remain in that position by hydraulic diflerential latchin pressure between the spools IOI and I as applied through the line I10a and port I10 to hold thisvalve latched in the position shown after the cam point I50 has again rotated away from the valve plunger I51 and will remain in this latched position so long as the pressure is maintained in the annular grooves I02 and I02.

Each of the other valves- I00 and I10 associated with the disc cam I25 is also provided with from the line 001 to a pressure supply line I00 having one branch line I99a connected to the valve I43 and the other branch line I99b connected to the valve I10. The valve I43, Figure 4, has a pressure port 200 to which the line I99a is connected and a drain or exhaust port I connected through a suitable drain line 95k to the drain line 95 for return of fluid to the reservoir 18. Whenever the valve plunger I42 is moved outwardly against its compression spring by either of the cam points I59 or I13 the pressure port 200 is opened to a differential annular groove 202 formed by a large spool 203 and a smaller spool 204 of the valve plunger I42, while the drain port 20I is closed whenever the pressure port 200 is opened to the annular groove 202, 'as shown in Figure 6. Thus, whenever pressure is applied to the annular groove 202 the diflerential areas between thespools 203 and 204 will normally cause the valve plunger I42 to be hydraulically latched in outward position away from the disc cam I as shown in Figure 6.

Similarly, in the valve I10 the pressure line I99b is connected to a pressure port 205 which communicates with a differential annular groove 206 formed by a large spool 201 and a smaller spool 208 of the valve plunger I12. A drain port 209 is connected through a drain line 952' to the drain line 95 for return of fluid to the reservoir 18. These ports are alternately connectable to the differential annular groove 206 in such a way that whenever the plunger I12 is moved out wardly against its compression spring I12a to connect the pressure port 205 to the annular groove 206 the plunger will be latched in outward position by hydraulic pressure.- Both valves I43 and I16 will remain in such position so long as pressure is maintained in the line I99, I99a, and I99b from the valve I95.

The pilot control valve I64 has a second annular groove 2I0 in addition to the annular groove I61 so arranged that when the valve I61 14 tion of the tracer head while arresting the feedingmotion.

With the machine set for automatic progression, with the tracer selector valve in "hand position and the progression selector valve in in position, whenever the tracer 48 is undeflec'ted the valve I64 is in its normal position,

' shown in Figure 16, permitting the saddle and is in its normal position under the influence of the compression spring I66 the return lines 8I and 82 from the saddle and table actuating cylinders 25 and 38 respectively are connected through the tracer selector valve 83 to the line 9I through the annular groove 93 in the progression selector valve 92 to the line 2 connected to the pilot control valve I64, and then through its annular groove 2"! out through a line 2I2 and a branch line 2I3 to the valve I56 and through annular groove 2I4 provided in its valve plunger I51 to a drain line 959 connected to the drain line 95 for return of fluid to the reservoir 18 when the valve plunger I51 is moved outwardly away fromthe disc cam I 25 by the cam points I59 or I13. Whenever fluid pressure is applied to actuate the pilot control valve I64 against the compression spring I 66 the line 2 will be blocked off at this valve I64 to thereby prevent operation of the feeding movement of the saddle and table cylinders 25 and 36. Thus, the operation of the valve I64 when in normal position under the influence of the compression spring I66 is to block the motor return line I22 'to prevent rotation of the tracer head rotating motor I06 while permitting the saddle and table cylinders to effect feeding motions, and when the valve I64 is moved against its compression spring I66 by fluid pressure in its pressure chamber I9I the return line from the hydraulic tracer rotating motor I06 will be opened as described to the drain line 95 while at the same time closing off the line 2 from the feeding cylinders to thus permit rotatable cylinders to feed while preventing rotation of the tracer rotating motor. tracer is deflected by engagement with the proflle pattern at the end of a longitudinal feeding stroke the pilot valve I64 will be moved against its compression spring I66 by fluid pressure in chamber I9I to arrest the saddle and table feeding movements while initiating rotation of the tracer head by the hydraulic motor.

There has thus been provided a tracer operated pilot control valve constituting a mechanism for alternately instituting a feeding motion or a change in direction of the feeding motion. The tracer further operates as a trip control member or device engageable with the profile pattern to provide the sole means for arresting the feeding movement and initiating a change in direction for the feeding movement between the cutting tool and the work.

When the tracer 48 engages the profile pattern at the point 51, Figure 10, and becomes deflected starting rotation'of the profile tracer rotating motor I06, the tracer head 41 and the synchronously rotatable disc cam I25 connected thereto begin to rotate in a clockwise direction, Figures 4 and 16. As a result, the cam point I59 of the disc cam I25 moves away from the plunger I51 of the valve I56, Figure 4, but the valve plunger I51 remains in its outer position by the hydraulic latching pressure coming in through the line I18a until the tracer again becomes undeflected as described. Valve plunger I 42 of the valve I43 at this time rides out of the detent notch I39, which does not move the plunger sufflciently far outwardly to cause the fluid pressure in the pressure port 200 to effect hydraulic latching of the valve plunger I42 or otherwise change the fluid connections tothe valve so that the plunger remainsunlatched and moves toward the disc cam I25 by its spring I4I after it leaves the detent notch I39, assuming the unlatched position shown in Figures 4 and '7. The valve rotate, the tracer becomes undeflected .by being rotated away from the obstructing surface of the profile pattern so that it ultimately returns to its undeflected position which disconnects pressure from the line H811 and connects this line to drain line 95a to allow valve plunger I51 of the valve I56 to become unlatched and move toward the disc cam I25, under the influence of the spring I51a, to the position shown in Figure 6. It is to be noted, Figure .6, that whenever the valve -plunger I51 of the valve I56 is in unlatched position, the pressure supply line [18a will be closed off at the annular groove 229 in the plunger I51.

At the same time the respective pressure chambers I and I86 for actuating the motor reversing valve I50 have their respective lines blocked off at the respective annular grooves I83 and I88 Whenever the as'npev of the valve I55 so that when the valve I55 is unlatched the valve plunger I52 of valve I50 may not be shifted When pressure in line Ilsa is cut off by return of the tracer 40 to undefiected position, the pilot control valve I54 is positioned in its normal position shown in Figure 16 and held therein by its spring I55 since pressure from. the line as and the associated line II8b which may be connected through the annular groove I'l8c of valve plunger I42 of valve I43 to the line IIIld connected to the pressure chamber Isl of the pilot control valve I54, is cut ofl at this time at the unlatched plunger I42 of the valve I43. This positioning of the pilot valve I54 would normally stop rotation of the tracer motor I05. However, its return line I22 is now connected through'the annular groove Iin the progression selector valve -92 to the line I53 and through the\ annular groove I5I in the valve plunger I52 of the motor reversing valve III to the line I53!) and the line I53 to the line I52 connected to the control valve I43. With the control valve. plunger I42 in the unlatched position the line I52 is connected through its annular groovel5l to the line I50 connected to the control valve I55, which valve is now in the unlatched position due to the tracer being undeflected and connects the line I50 through annular groove I58 of the plunger I51 to the drain line 05! and the drain line 95 for return of fluid to the reservoir I8 to permit continued rotation of the motor I0 5. The line I530 at this time is blocked at the annular groove III of the valve plunger I12 of the valve "0 since it is in latched up position as described.

The rotation of the tracer head 40a and the disc cam I continues through 90:of rotation until the cam point I59 engages the plunger I42 of control valve I43 which moves the plunger outwardly to block off the line I52 carrying the return flow from the hydraulic motor I05 at the valve I43 to thus stop rotation of the motor I05. Since the valve plunger I12 in the valve "0 is still latched up it continues to block off the line I53c connected to the line I52 and I53 so that there is no escape of fluid therethrough to prevent the stopping of the motor I05. Also, the

. plunger I51 of the valve I55, which is now unlatched, rides into the detent notch I40 as shown in Figure 6 so as to effect a positioning of the disc cam I25 and tracer head in the 90 rotated position preparatory to the cross indexing movement.

At this time the return lines ill and 82 from the saddle and table feeding cylinders are connected through the tracer selector valve 53 to the line 9| and through the progression selector ,valve 92 to the line 2 which is connected to the pilot control valve I54 which at this time is in its normal position under the influence of its spring I55 so as to connect the line 2| I through the annular groove 2I0 to the line 2I2 to which is connected a line 2I2a connected to the motor reversing valve I50. At this time this valve has its plunger I52 so positioned that its annular groove 2 connects the line 2I2a to a line which, in turn. is connected to one side of a metering or progression cross indexing movement cylinder 2I5. Figures 15 and 16. This metering cylinder 2I5 has a freely moving piston 2II slidably mounted in its bore 2I8 of the cylinder 2I5 so as to form a chamber on one side thereof to which is connected the line 2I5 and a chamber on the other side thereof to which is connected a line 2". The obiect of this cylinder is to pro- 16 vide an arrangement for metering or permitt a predetermined volume of fluid to flow into the cylinder either through the line H5 or the line 2I8 before the flow is positively arrested by the stopping of the piston 2 H at the end of its stroke of travel in the cylinder bore 2I5.

The extent of back and forth travel of the piston 2II may be varied to suit the volume of oil it is desired to permit the lines H5 and 2I9 to discharge into the cylinder 2I5. This comprises an adjustable abutment screw 220 appropriately mounted in a threaded nut 22I fixed to the cylinder housing 2I5 by a suitable bracket 222 and which screw may be rotated by a suitablehand wheel 223 having an indicating strip or dial 224 appropriately graduated for indicating the amount of each cross indexing movement the operator may select for the automatic progression operation. Thus. as the discharge from the table and saddle cylinders begins to enter the metering cylinder 2I5 through the line 2I5 as described the piston 2", which at this time is against the end 220a of the abutment screw 220, will move away from the screw 220 to the opposite end of the cylinder 2I5 until it engages the positive abutment surface 220!) and comes to a stop so that no further fluid may enter the cylinder bore 2I8 from the line 215. Discharge through the line 2I9 passes through the annular groove 234 of the reversing valve I which at this time is connected to the line 234a and through a hydraulic resistance 2341) to the drain line 957. When fluid is being discharged out of the metering cylinder 2I5 through the line 2I5, the valve plunger I52 of the motor reversing valve is-so positioned that the line 2I5 is connected through the annular groove 2 to the line 2340 and the resistance 234D to the drain line 95a, in both cases the fluid resistance servin to control the movement of the metering cylinder piston 2". By thus volumetrically metering the discharge from the table and saddle cylinders the amountor distance of cross indexing progression movement may be accurately obtained independent of the feed rate setting for these cylinders as determined by the setting of the tracer head eccentric I2.

By rotating the hand wheel 223 the graduations on the scale 224, arranged to move axially with the screw 220 indicates the amount of cross travel in inches. When cross indexing movements are being obtained by table movement the scale figures 224 are utilized in connection with the reference line 225.v provided on the cylinder 2I5 whereas when the cross indexing movements are to be effected in the vertical direction the reference figures 22% are utilized in connection with the reference line 225. The different scales are required because the table cylinder 31 is usually oflarger diameter than the vertical saddle cylinder 24 and therefore the volumetric displacement for a given amount of cross indexing movement will vary in accordance with the cylinder sizes, this being automatically taken care of by the multiple scales 224a and 224b. when, for example, automatic progression is to be effected at an angle as in the case of the work surface W-2, Figure 11, the amount of cross indexing movement may be readily selected by utilizing a setting somewhere between the two scale readings shown on the scale 224.

Discharge from the table and saddle cylinders finally moves the metering cylinder piston 2II up against the abutment 22011 by discharging versing valve into the drain line 95f as described. Thus piston 2" stops causing pressure to immediately build up in the cylinder and in the line 2 I 5, and through the annular groove 2I4 of valve plunger I52 of valve I50, in the line 2I2a, the line 2I2, and the line 2I3 which is connected to the valve I56 and is at thistime closed off from the drain line 95g at the annular groove 2I4 by the plunger I51 since it is in unlatched position as shown in Figure 6. This pressure in the line 2 I 3 and 2 I2 is also transmitted through a branch line 221 connected to a pressure chamber 228 of the latching control valve I95 which causes its plunger I96 to be depressed against the spring I91 so as to close off pressure from the pressure supply line 807' while at the same time connecting the lines I99, I99a and I99b for the hydraulic latching mechanism of the respective valves I43 and I10 to a drain line 95k to thus release the latching pressure in the valves I43 and I10 and permit them to unlatch and move radially toward the disc cam I25.

The unlatchin of the valve I10 by the control valve I95 connects the line I63c, carrying the return flow from the hydraulic tracer motor I06, through the annular groove I1I of the plunger I12 to the drain line 95h connected to the drain line 95 to thus again initiate rotation of the hydraulic tracer motor I06, the tracer head 41, and the disc cam I25 to thus stop the cross indexing movement and cause a change in direction of the tracer head 48a. Discharge from the motor I06 is then also conducted from the line I63 through the line I62, the annular groove I6I in the valve plunger I42 of the valve I43 out through the line I60 to the control valve I56 and through the annular groove I58 of its valve plunger I51 to the drain line 95 f connected to the drain line 95 after cam point I59 rotates out from under the plunger I42 of the valve I43. Rotation of tracer head and disc cam I25 then continues for another 90 of rotation until the cam point I13 of the disc cam I25 arrives at the position shown in Figure '7 to again move the plunger I51 of the valve I56 outwardly against the spring I51a. As a result, pressure in the line 221 holding down the valve plunger I96 of valve I95 is relieved by discharge through the line 2I3 through the annular groove 2I4 of the valve plunger I51 of the valve I56 to the drain line 95g connected to the drain line 95, thus again reestablishing the latching pressure in the lines H391: and I99b of the respective control valves I43 and I 10. Movement of the control valve plunger I51 to its outward position by the cam point I13 closes off the drain line 95f1fr0m connection with the line I60, Figure '7, carrying return flow from the hydraulic tracer rotating motor I06 so as to arrest the rotation of the motor. The annular groove I58 connects the line I60 to the pressure line I55 so as to again apply pressure to the motor return line I22 to stop the motor. The line 2I3 is at the same time connected to the drain line 95g by the valve I56 so as to reestablish the longitudinal feeding movement.

The valve I10 has its plunger I12 moved outwardly by the cam point I59 which causes it to latch in its outward position so as to close of! the line I630 at its annular groove III to prevent fluid from escapin to drain line 95h from the motor return line I22 and associated connecting lines to the line I630 as described.

It is tobe noted that the cam point I13 of the disc cam I25 does not project radially as far outwardly as the cam point I59 so that the control valve plunger I51 is not moved as far radially outwardly by the cam point I13 as the cam point I59. As a result when the cam point I13 is controlling the outward position of the plunger I51, Figure 7, pressure from the line I18a is connected into the annular groove 229 formed in the valve plunger I51 by the spool I8I and the spool I89 through the annular groove I88 in the valve body I56 and then into the line I81 connected to the pressure chamber I86 of the motor reversing valve I 50 to cause its plunger to shift the opposite direction to the position shown in Figure 16. At this time fluid is discharged out of the pressure chamber I of the valve I50 through the line I84 to the annular groove I03 in the valve I56 and then through the annular groove I92 of the valve plunger I51 and into the drain line 95l, which is now opened to the annular groove I92 due to the lower cam point I13 which was not the case when the high cam point I59 lzeld the valve in the position shown in Figure 4.

Thus, the valve plunger I52 of the motor reversing valve I50 is shifted to the position shown in Figure 16 the next time thetracer is deflected to reverse the connections to the profile tracer motor I06 for counterclockwise rotation of the tracer head since now pressure from the line 80h passing through the annular groove I5I of the valve plunger I52 may enter the line I53 and through the annular groove I20 of the valve plunger 94 of the valve 92 comes into the line I22 connected to the hydraulic tracer rotating motor I06, the line I2I then becoming the motor return or drain line connected through the annular groove I I9 of valve plunger 94 to the line I69 which is connected through the annular groove I68 of the plunger I52 of the valve I50 to the line I63a and into the line I63 connected to the pilot control valve I64. Thus, when thepressure in the chamber I86 of the valve I50 builds up after shifting its plunger I52 to the position shown in Figure 16, it will discharge out through the line 23I into the line I to the pressure chamber I9I- of the valve I64 to shift it downwardly and permit the return flow from the hydraulic motor I06 through the line I63a and line I63 to pass through the annulargroove I61 of the valve plunger I65 to the drain line 957' to thus again start rotation of the hydraulic motor I06 in the opposite direction. The cycle and sequence of valve operation of the various control valves will take place as described except that now the disc cam I25 will rotate in the opposite or counterclockwise direction of rotation. Thus, when the tracer again engages the profile pattern the cycle just described will be successively repeated until the work surface to be machined has been entirely scanned by the automatic progression movement.

When the back and forth longitudinal feeding movement terminates at each end by engagement of the tracer 48 with converging surfaces of the profile pattern, such as at the point 63 in Figure 10, it is obvious that it is necessary to rotate the tracer head more than 90 before instituting the cross indexing movement or else this cross indexing movement would gouge in beyond the desired profile 53 of the work surface to be machined. In such instances the tracer, of course, will remain deflected even after the tracer head has been rotated through the initial 90, so that pressure will continue to be applied by the line I18b through the latched up valve I43 which is engaged by either cam point I59 or I13 after 90 p of rotation and the line I18d to maintain the depressed against its spring I66 so as to continue rotation of the hydraulic tracer rotating motor I06 even after 90 of initial rotation have been completed. This rotation will continue beyond 90 with the valve I64 depressed until the tracer 48 finally becomes undefiected by being rotated sufficiently away from the converging portion 68 of the profile pattern. When the tracer is finally undefiected pressure from lines 96, I18 and I181: through valve I43 is removed and is connected to the drain line 95a by the profile tracer valve. This permits the return of the valve I64 to its normal position under the influence of the spring I66 when the tracer 48 becomes undefiected to now start the cross indexing movement of the table andsaddle cylinders at an angle, represented by the line 65, Figure 10, while arresting rotation of the tracer rotating motor I06. The angular cross indexing movement continues a distance as determined by the setting of the metering cylinder 2I6 and upon completion of the movement of the piston 2I1 of the metering cylinder the fluid pressure rise causes actuation of the valve I95 to take place which uniatches the valve I43 to permit the final amount of rotation of the motor I06 to the total of 180 of rotation preparatory to initiating again the longitudinal feeding movement of the tracer in the opposite direction along the line 61, Figure 10. This arrangement is so designed that should the tracer meet an obstruction and become deflected in traveling along the angular path of cross indexing movement 65, it would be momentarily stopped while the tracer head would be rotated away from the obstruction by the motor I06 and as soon as the tracer again became undefiected by this rotation, the motor would be stopped and the feeding again restarted so that there is no possibility of the tracer and cutter overtraveling the desired profile surface 53 of the work under any irregular condition of its .work surface when initiating reversal of the iongitudinal feeding movement against converging or reentrant surfaces, such as at 63 in Figure 10.

With this arrangement it is obvious that the length of cross indexing movement, whether effected perpendicular along the line 58 or in an angularly related direction along the line 65, as indicated in Figure 10, will be the same and determined by the setting of the adjusting screw 220 of the metering cylinder 2Il6. Thus in the automatic operation of the machine to completely scan work surfaces such, as shown in Figure 11, the machine may be set in operation and will thenceforth automatically complete the scanning of the-entire area of each work surface without attention upon the part of the operator.

It will be noted that when worknig or converging surfaces with acute angular relationship to the direction of longitudinal feeding movement as indicated at 65 in Figure 10, there will be a tendency to decrease the actual cross indexing movement so as to cause the longitudinal feeding lines of movement to be somewhat closer together in automatically working between angular converging surfaces, as indicated in Figure 11. This is ordinarily not objectionable but if it is desired to maintain a substantially uniform cross indexing motion in the interest of maximum production it is merely necessary for the operator to appropriately adjust the hand wheel 223, Figure 15, of the metering cylinder 2I6 to increase the length of cross indexing movement along the line 65 when the converging surfaces are'approached during the automatic progression movement to maintain a substantially uniform actual spacing between each longitudinal path of feeding.

When it is desired to operate the machine having the automatic progression control mechanism described for normal manual tracer control movements or for conventional profile or three-dimensional automatic control operations it is preferable to eliminate automatically the operation of the various control devices and control valves not being utilized during the normal operation of the machine. This also minimizes wear by needless operation of parts not required to effect the desired machine operation and also increases the sensitivity of those parts actually being utilized. More specifically, the operation of the control valves I43, I56, and I12 which are actuated by the disc cam I25 is automatically eliminated during normal automatic profiling or tracing'operations. This also avoids the tendency of the valves to restrict freedom of rotary movement of the tracer head.

In order to accomplish this, the progression selector valve 92 is so arranged that when moved to its out position 92a the pressure line 80k connected to the main pressure line 00 from the hydraulic pump 11, and which is normally closed off at the annular groove 236 of the valve plunger 94, is connected through the annular groove I11 to the line I18 having the branch line I18a which maintains pressure in the latching arrangement of the valve I56 when its plunger I51 is moved outwardly by the high point I59 of the disc cam I as described. Also, at the same time pressure is maintained in the latching means for the valves I43 and I10 through the line 809' of the pressure line 80 as described so that when the machine is to be put in manual or normal automatic profile tracing operation and the progression selector valve is positioned in the out posi- 40 tion 92a, merely by rotating the hand wheel 96a or by rotating the tracer head under power operation by the motor I06 as when tripping the tracer selector valve 83 from hand to automatic as described, the cam point I59 rotates around and strikes the various valve plungers I51, I42, and I12 to cause them all to be latched up out of the way of the disc cam I25 so that thereafter this disc cam and the tracer head may be freely rotatable without actuation of the valve plungers of these valves and cooperating control valves and metering cylinder described. Thus, whenever the operator cuts out the automatic progression cycle by appropriately manipulating the progression selector valve the automatic progression control mechanism is automatically rendered inoperative.

As a safety feature in connection with this mechanism there is provided a supplemental control valve 232 which is actuated by overdefiection of the tracer 48 as might occur in running into an obstruction, so as to connect pressure from the line 80m connected to the main pressure line 80 which supplies pressure to the annular groove 233 formed in the valve 232. When the tracer 5 48 is overdefiected the valve 232 to the line 234 is moved to connect fluid pressure through line 234 to the pressure operating chamber 235 of the progression selector valve 92 to shift valve plunger 94 to the out position 92a. The line 96 from the tracer control valve 41 which is supplied by pressure from the line 80d when the tracer 48 is overdefiected now becomes connected through the annular groove 99 of the valve plunger 94 to a line I00 connected to the pressure chamber IOI which moves the tracer sethe feeding motion of the table and saddle cylinders and cause rotation of the tracer head to overcome the overdeflection of the tracer 48 and to thereby protect the machine operation when set in any of its operating cycles.

There has thus been provided in a pattern controlled milling machine an arrangement capable of automatically scanning in an automatic progression machining operation an entire threedimensional work surface without attention upon the part of the operator.

There has also been provided in such a machine an arrangement whereby the cross indexing movement of the automatic progression operation may be radially effected in any angular direction by the mere adjustment of control devices of the machine without in any way altering the position of the work piece in the machine or changing the general set-up of the machine structure.

There has also been provided in a pattern controlled milling machine capable of automatically scanning three-dimensional work surfaces of irregular profile, an arrangement permitting automatic reversal of the scanning movement in connection with converging surfaces which automatically accurately accommodates itself to any irregular configuration of the profile of the work piece without attention upon the part of the operator.

What is claimed is:

1. In a pattern controlled milling machine having a pair of relatively movable slides, fluid pressure actuating means for said slides, a work piece and pattern mounted on one of said slides and a cutter and tracer mounted on the other of said slides, and directional control means in connection with said tracer for eifecting the simultaneous operation of said slides by said fluid pressure actuating means to determine the resultant direction of movement of the work and cutter, the combination of fluid pressure control means to effect orientation of said directional control means to a predetermined position to effect a relative longitudinal feeding movement between said cutter and work piece, and further fluid pressure control means rendered operative by the engagement of said tracer with said pattern during said longitudinal feeding movement to effect a relative cross indexing movement of cutter and work piece normal to said longitudinal feeding movement.

2. In an automatic die sinking machine having a pair of relatively movable members, fluid pressure actuating means for said members, a work piece and pattern mounted on one of said members and a cutter and tracer mounted on the by the engagement of said tracer with said pat- 22 distance for each engagement of said tracer with said profile pattern.

. 3. In a pattern controlled milling machine adapted to perform an automatic progression operation on a work piece, the combination of a tracer and cutter movable relative to a pattern and work piece, means operative to cause reversible longitudinal feeding movements of the tracer and cutter relative to the pattern and work, means rendered operative by the engagement of the tracer with the pattern to cause a cross indexing movement normal to said longitudinal feeding movements when said cross indexing movement is taking place in a direction away from the surface of the pattern at the point of engagement of the tracer therewith, and further means to cause a cross indexing movement in a direction substantially parallel to the profile pattern surface engaged by the tracer when said cross indexing motion is taking place toward the surface of said pattern at the point of engagement of the tracer therewith.

4. In a pattern controlled milling machine adapted to perform an automatic progression operation on a work piece, the combination of a tracer and cutter movable relative to a pattern and work piece; means operative to cause reversible longitudinal feeding movements of the tracer and cutter relative to the pattern and work, means rendered operative by the engagement of the tracer with the pattern to cause a cross indexing movementnormal to said longitudinal feeding movements when said cross indexing movement is taking place in a direction away from the surface of the pattern at the point of engagement of the tracer therewith, further means to cause a cross indexing movement in a direction substantially parallel to the profile pattern surface engaged by the tracer when said cross indexing motion is taking place toward the surface of said pattern at the point of engagement of the tracer therewith, and means for maintaining a substantially constant amount of cross indexing movement, independent of the rate of said longitudinal feeding movement, for any configuration of the profile pattern being scanned.

5. In a pattern controlled milling machine adapted to perform an automatic progression operation on a Work piece, the combination of a tracer and cutter movable relative to a pattern and work piece, means operative to cause reversible longitudinal feeding movements of the tracer and cutter relative to the pattern and work, means rendered operative by the engagement of the tracer with the pattern to cause a cross indexing movement normal to said longitudinal feeding movements when said cross indexing movement is taking place in a direction away from the surface of the pattern'at the point of engagement of the tracer therewith, further means to cause a cross indexing movement in a direction substantially parallel to the profile pattern surface engaged by the tracer when said cross indexing motion is taking place toward the surface of said pattern at the point of engagement of the tracer therewith, and means for maintaining a substantially constant amount of cross indexing movement independent of the rate of said longitudinal feeding movement for anyconfiguration of the profile pattern being scanned, including means for adjusting the amount of cross indexing movement during the continuous automatic operation of the automatic progression operation to maintain a substantially constant amount of cross indexing movement normal to said direction of longitudinal feeding movement.

6. In a pattern controlled milling machine having a cutter and a tracer head movable relative to a work piece and pattern, and means for effecting an automatic progression machining cycle between said cutter and work piece comprising fluid pressure operating means for circumferentially orienting said tracer head in a predetermined direction of longitudinal relative feeding movement of cutter and work piece, fluid pressure control means rendered operative by engagement of said tracer head by said pattern to arrest said longitudinal feeding movement and reorient said tracer head to cause relative cross indexing movement of said cutter and work, said last-mentioned means including means for the circumferential orientation of said tracer head by operation thereof by a reentrant surface of said pattern during longitudinal feeding movement to maintain the cross indexing movement at all times within the confines of the work surface to be machined.

'7. In an automatic pattern controlled machine tool having a pair of actuable slides, fluid operable means for actuating said slides, a common rotatable rate and direction control member associated with said fluid operable means for controlling the rate and resultant direction of simultaneous operation of said slides, fluid pressure means for changing the effective direction of said common rate and direction control member, a trip operated control means actuated by engagement with a pattern of said machine to arrest movement of said slides, and cause a change in eiIectiv'e direction of said rate and direction control member, and means rendered operative by the disengagement of said trip control means from said pattern to cause movement of said slides when said rate and direction control member is positioned in a. predetermined effective direction.

8. In a pattern controlled milling machine having a pair of fluid operable slides, a common rate and directional control member rotatable to determine the direction of resultant movement of simultaneous operation of said slides, fluid pressure actuating means for rotating said common member, a cam operated fluid pressure control device synchronously rotatable with said common member, a tracer operable when deflected by engagement with a control pattern in said machine to rendersaid fluid pressure means for rotating said common member operative, means whereby said cam operated fluid pressure control device effects rotation of said common member to a predetermined position, fluid pressure control means operable to cause a predetermined distance of relative travel of said slides independent of the rate of the resultant movement of said slides when said common member has been rotated to a predetermined position, and further fluid pressure control means operable by said cam operated fluid pressure control device to effect further rotation of said common member to another predetermined position to again institute movement of said slides.

9. In a pattern controlled milling machine having a 360 profile tracer head having a tracer adapted upon deflection to cause rotation of said head for changing the eflective direction of relative movement of a cutter and work piece of the machine and to arrest said rotation and cause relative movement of the cutter and work when undeflected, the combination of an auxiliary hydraulic control means adapted to maintain said tracer head in a predetermined eflective direction of relative movement of cutter when undefiected to effect longitudinal feeding movement of cutter and work, means rendered effective by the deflection of said tracer during said longitudinal feeding movement to cause said tracer to rotate to an effective direction substantially perpendicular to said longitudinal feeding movement and to institute movement of cutter and work in said perpendicular direction for a predetermined distance independent of the rate of said relative longitudinal feeding movement, and means operable independent of the movement of said tracer to cause further rotation of said tracer head to reverse the direction of longitudinal feeding movement after said cross indexing movement has been completed.

10. In a hydraulic control system for a pattern controlled milling machine arranged to perform profiling operations or automatic progression operations by relative movement of work and tool therein, a rotatable 360 profile tracer head having a tracer adapted to engage a pattern, fluid pressure means for rotating said tracer head to predetermined circumferential positions for determining the direction of relative movement of work and tool, a control tracer mechanism openable for selecting profiling or progression operations for the machine including a series of sequentially operated control valves actuated by the rotation of said tracer head arranged to effeet the orientation of said tracer head in predetermined directional positions, and fluid pressure latching means associated with said control valves operable to determine the sequential operation of said control valves.

11. In a hydraulic control system for a pattern controlled milling machine arranged to perform profiling operations or automatic progression operations by relative movement of work and tool therein, a rotatable 360 profile tracer head having a tracer adapted to engage a pattern, fluid pressure means for rotating said tracer head to predetermined circumferential positions for determining the direction of relative movement of workvand tool, a control tracer mechanism operable for selecting profiling or progression operations for the machine including a series of sequentially operated control valves actuated by the rotation of said tracer head arranged to effeet the orientation of said tracer head in predetermined directional positions, and fluid pressure latching means associated with said control valves operable to determine the sequential operation-of said control valves, and means rendered operative by said control tracer mechanism whereby said latching means renders said control valves inoperative when the machine is adjusted for profile operations.

12. In a hydraulic control system for a pattern controlled milling machine capable of performing automatic progression scanning operations on a work piece having a rotatable 360 profile tracer head including a tracer for controlling the relative movement of work and tool and the direction of said movement, a control valve operable for selecting manual directional control of said tracer head or for selecting power directional control therefor for automatic profiling operations and a progression selector controlmechanism including a selector valve operable to adjust said machine for manual and automatic profile operations or for automatic progression operations, cooperating fluid pressure control means comprising a series of sequentially operated control valves. actuated by a control cam rotatable synchronously with said tracer head, a reversing means for changing the direction of rotation of said tracer head. a pilot control valve operable by the deflection of said tracer to alternately cause relative movement of work and tool or a change in efiective direction of said relative movement, and a fluidpressure metering device for acc irately determining the distanceof relative movement of work and tool when said tracer head is positioned in predetermined directions of eilective relative movement of work and tool.

13. In a pattern controlled milling machine adapted to .perform automatic progression machining operations on a work piece, a 360 rotatable profile tracer head, a fluid pressure motor for rotating said tracer, fluid pressure actuating means for effecting relative feeding movement of work and tool in said machine, a fluid pressure control means operable bv the deflection and undefiection of said tracer ior alternately eflecting said relative feeding of work and tool or the rotation of said-tracer head during automatic progression machining operations including the combination of a series of sequentially operated control valves, a disc cam rotatable for actuating said valves in predetermined sequential relationship, means for rotating said cam and tracer head in synchronism, and adjustable clutch means interconnecting said cam and tracer head for re-' orienting said cam relative to said tracer head to effect any angular direction of automatic progression movements.

14. In a fluid pressure power circuit for a pattern controlled milling machine having a 360 profile tracer head including a tracer for controlling the direction and rate of relative movement of work and tool in the machine, a tracer selector valve for adjusting the tracer head for profiling operation of the machine, a manually operable progression selector valve, a hydraulic control means rendered operative by said progression selector valve for setting up an automatic progression operation of the machine including the combination of a series of sequentially operated control valves actuated by the direction of movement of said tracer head, a reversing valve actuated by said sequentially operated valvesfor directionally positioning said tracer head, a pilot valve operable by the deflection of said tracer for controlling the direction and relative movement in said direction of work and tool, a fluid metering device controlling the distance of relative movement of work and tool for certain predetermined directional positions of said tracer head and a latching control valve rendered operative by said fluid metering device for modifying the operation of said sequentially controlled valves during their operation by the direction of movement of said tracer head.

15. In a pattern controlled milling machine having a fluid pressure actuating circuit for effecting an automatic progression machining operation between Work and tool therein, the combination of a tracer head having a .tracer, means for effecting a predetermined distance of travel 26 of work and tool for certain directions of relative movement thereof, and a latching control valve for controlling the movements of said sequentially operated valves in conjunction with their control by the rotation of said tracer.

v 16. In a fluid pressure control circuit for effecting predetermined relative movements of work in a machine tool, the combination of a directionally eflective tracer for determining the path of relative movement of work and tool, means for directionally positioning said tracer,-a series of three sequentially operate fluid pressure control valves actuated by the directional movement of said tracer, fluid pressure latching means associated with said valves rendered operative by the actuation thereof by the direction of movement of said tracer, and a latching control valve associated with said valves for rendering said latching means inoperative by the movement of said tracer head to predetermined directional positions.

17. In a machine tool having a pair of relatively movable members, actuating means for effecting a relative movement between said members, directional control means for varying the direction of said relative movement, a fluid pressure control system for said actuating and control means including a series of sequentially operable fluid pressure control devices comprising a trip operable control valve actuated by the relative movement of said members to predetermined positions, a reversing valve for changing the direction of operation of said directional control means operated by the actuation of said trip control means,

a pilot control valve rendered operative by the operation of said trip control means and the operation of said reversing valve to stop operation of the actuating means for said machine members and to render said direction control means operative, a control valve rendered operative by the initial operation of said directional control means to maintain the continued operation of said directional control means after the tripping of said trip control means, a second control valve renderedoperative after a predetermined change of direction of relative movement'to stop operation of said directional control means and cause said actuating means to become operative, a fluid pressure metering device permitting said actuating means to "continue operation for a predetermined distance of relative movement of said machine members, a latching control valve operable to shift the position of said second-mentioned control valve and a third control valve to again arrest operation of said actuating means and cause actuation of said direction control means, and means whereby said first and third control valves are actuated upon a further predetermined amount of change in direction of relative movement of said machine members by the operation of said directional control means to arrest further operation of said directional control means and reestablish operation of said actuating means for said machine members.

18. In a fluid pressure control circuit for a pattern controlled milling machine having a trip control-tracer for determining the direction and relative movement of work and tool therein, fluid pressure control means associated with fluid pressure actuating means for rotating said tracer head to predetermined directional positions to automatically effect predetermined directions of relative movement of work and tool, a reversing valve for changing the direction of rotation of said fluid pressure actuating means, a pilot control valve operable by the deflection of said tracer to alter- 

